Posted
by
msmash
on Thursday May 17, 2018 @01:31PM
from the up-next dept.

An anonymous reader shares a report: Later this year, a small part of the International Space Station will become 10 billion times colder than the average temperature of the vacuum of space thanks to the Cold Atom Lab (CAL). Once it's on the space station, this atomic fridge will be the coldest known place in the universe and will allow physicists to 'see' into the quantum realm in a way that would never be possible on Earth.

In a normal room, "atoms are bouncing off one another in all directions at a few hundred meters per second," Rob Thompson, a NASA scientist working on CAL explained in a statement. CAL, however, can reach temperatures that are just one ten billionth of a degree above absolute zero -- the point at which matter loses all its thermal energy -- which means that this chaotic atomic motion comes to a near standstill.

CAL uses magnetic fields and lasers traps to capture the gaseous atoms and cool them to nearly absolute zero. Since all the atoms have the same energy levels at that point, these effectively motionless atoms condense into a state of quantum matter called a Bose-Einstein condensate. This state of matter means that the atoms have the properties of one continuous wave rather discrete particles.

Although Bose-Einstein condensates have been made in labs on Earth, gravity causes the particles to sink to the bottom of the device. Yet in the microgravity of low earth orbit, the Bose-Einstein condensate can hold its wave form for much longer—up to ten seconds—which allows researchers to better understand its properties.

You're assuming the "average temperature of space" is 1K? I believe in interstellar space it's closer to 3K and near earth it's much higher. So maybe a closer estimate is 8x10^-9K. Of course I could be wrong.. please correct me.

Why the hell they couldn't just type the number instead of wearing out everyone's 0 key?

No one said anything about the average temperature of space. The coldest place known in the universe (outside of a lab) is the Boomerang Nebula [wikipedia.org], and it does indeed have a measured temperature of 1 K.

Obviously the average temperature of the vacuum of space is some value, let's call it T_v.If the temperature of the atomic fridge - let's call it T_f - is 10 billion times colder than T_v, then:T_f = T_v - 10,000,000,000 T_v

The summary also states that the atomic fridge "can reach temperatures that are just one ten billionth of a degree above absolute zero".So, assuming they're talking in Kelvin (or a system with the same scale but a different offset), T_f = 1/10,000,000,000 degrees Kelvin.

The parent thinks that the article should have said 99.99999999% colder. Maybe "10 billion times as cold" would be acceptable too. Parent makes fun of the consequences of "10 billion times colder".

Cold does not exist per se; it is the absence of heat. What does 10 billion times the absence of something even mean? The sentence should have read that space is 10 billion times as hot as the fridge or that the fridge is one ten-billionths as hot as space. Oh, and remember than when talking temperatures, always convert to kelvin before doing the math (273 C is about twice as hot as 0 C).

What are you on about? X times smaller means "divided by X" in pretty much every context I've ever encountered. Is it linguistically logical? No. But very little about language is. Is it unambiguous anyway? Yes.

Well, no I suppose that's not *quite* true. "X times smaller" is the inverse of "X times larger", and there is some slight ambiguity there. 3x larger almost always means 3x as large as the reference size, but the words technically indicate 1+3, or 4x larger than it began. That hardly ever comes up though, unless there's a pedant around trying to stir up trouble. And as the scale increases the relative difference diminishes. It doesn't really make much functional difference if 10,000,000,000x colder is

Certainly "big" and "small" are useful terms - they're just *qualitative* rather than *quantitative* - they perform much the same role as a negative sign for addition - indicating the (one dimensional) vector direction in which quantities are interpreted.

The caveat of course being that we're talking proportion(multiplication) here rather than addition, so the inverse is division rather than subtraction. And likewise, the degenerate(identity) value is 1 rather than 0.

Saying "X times lower", "X times smaller" and "X times colder" is common in English, and everyone knows what it means. "Times" means multiplication. You can multiply by 10 to make X ten times bigger. You can multiply by 1/10 to make X ten times smaller. If you make X ten times bigger, and then make it ten times smaller, you end up right back where you started, which is what you would logically expect. Stop nitpicking.

Why not? You have an absolute reference point for length - 0m, against which all scaling takes place so that it makes sense, right?

You also have an absolute reference point for temperature - absolute zero, the temperature at which there is no more thermal energy to remove, even in theory, against which temperature scaling makes just as much sense. It['s only in the completely arbitrary Celsius and Fahrenheit scales that it appears nonsensical - but those don't get used in scientific calculations for exactly that reason (outside of chemistry and thermal flow, which are mostly interested in temperature deltas and critical event temperatures, neither of which care where zero is)

You can't even compute heat-engine efficiency using C or F them without getting completely bogus results, because they're completely bogus scales - as though we arbitrarily said the "zero point" on a ruler was actually 213.7meters from the beginning, so that a sheet of paper was approximately -213.7 meters thick - which would similarly make scaling lengths pretty much nonsensical.

Just because people know what it means doesn't mean it is correct. Its actually an imprecise description. Take "ten times lower" that a hilltop. Is that 1/10th the altitude of the hilltop, or is that 9 times the hilltop altitude below ground which makes 10 times after adding the hilltop, or does it mean ten times the hilltop altitude below ground?

"10x as high" is completely unambiguous. 10x higher is used to mean the same thing, but *is* technically ambiguous the words literally mean 10x+1 = 11x, but that's almost never how it's used (the exception generally being with percentages for some reason, probably because they're usually used for fractional changes).

"10x lower" is the inverse function. Make something 10xhigher, then 10x lower, and you get back to the original state. intuitively obvious

Take "ten times lower" that a hilltop. Is that 1/10th the altitude of the hilltop, or is that 9 times the hilltop altitude below ground which makes 10 times after adding the hilltop, or does it mean ten times the hilltop altitude below ground?

You could make the exact same objection to "ten times higher". You need to have a common reference point going up or down.

TFH is unambiguous because the reference point is obviously zero Kelvin.

Yep. And the coldness of space is something like a couple degrees Kelvin, which measures from absolute zero, the theoretically coldest temperature achievable, at which all heat has been removed from the system. And the only thermal reference point from which you can meaningfully determine thermal ratios, such as needed for thermodynamic efficiency calculations, or saying Thing A is X times hotter or colder than Thing B.

Seems the whole world is getting more and more tolerant of sloppy expression."One million times colder" is absolute semantic drivel. If it's logically valid, then what on earth does "one time(s) colder" mean?It's on the same level as "this beer tastes five times lousier". Anyone who uses it ought to be totally ashamed at their lack of expression skills and take up speaking Inuktitut or something.

Same as for "hotness" or any other colloquial term for equilibrium latent heat energy, a.k.a "temperature" - Kelvin (Celsius is arbitrary bullshit unsuitable for measuring anything other than temperature deltas, in which case the delta is the same as if measured in K)

I don't know - cryogenics is in large the art of cooling things off fast enough that ice crystals don't form and expand (as that ruptures cell walls). And this thing is so cold it makes typical cryogenic temperatures look positively balmy in comparison.

Assuming it were possible to drop the temperature to absolute zero, would an atom in this state be able to be observed, including its constituent parts? Could it be moved in one piece like a piece of matter?

Or would the fact it is at absolute zero cause it to fall to pieces (no pun intended)? How would quantum mechanics come into play in this scenario?

Each post is an independant test of the theory your posts may produce a black hole. Since the chance is as small as the orbital experiment producing a black hole, the fact you have posted hundreds of times provides no evidence.

No. They are not similar, each post has different text, going through a different conjunction of network traffic which would be the source of the black hole forming (or possibly the disk storage array reaching critical mass from a charged particle slightly altered in course from the traffic from the post), each post is obviously an independent trial with no effect on the probability of any others.

Well, a basic knowledge of physics would tell you that 1) black holes only form with ridiculous amounts of mass, which is a different unit than temperature, and 2) the normal effect of removing temperature from a thing and then stopping the experiment is that the temperature just comes back to average.

A vacuum has no temperature since temperature is a measure of the kinetic energy of the particles. In deep space we consider the temperature to be the equilibrium temperature an object will eventually reach, which is the temperature of the cosmic background temperature.

Anyway, one ten billionth of a degree over absolute zero is not 10 billions times colder than the average temperature of the vacuum of space. We really need journalists to have at least passed grade 9 science before writing about science.

Building and maintaining a system like this is very hard! Astronauts are often good scientists, but these laser cryogenic system require some deep specialization to keep running day to day. The impressive part of this to me is that in a few decades we went from 4-5 people in the world being able to build such systems and get them to work (once a month, maybe) to being able to strap a system to a rocket and have someone from a completely different field operate it in an environment where spare parts are at